multicenter randomized double-blind placebo-controlled study to investigate azvudine in symptomatic adults with covid-19 at increased risk of progressing to severe illness

Conditions: COVID-19 Respiratory Infection

Summary: to investigate whether treatment with azvudine reduces the risk of severe illness or death in patients who are at a potential risk of progressing to severe covid-19 infection.

the study is designed as a randomized, parallel, double-blind, placebo-controlled trial, in which all participants will be randomized to a test group or control group in a 1:1 ratio. the test group will be given azvudine in combination with conventional therapy excluding anti-viral therapy and observed for efficacy. the control group will be given placebo in combination with conventional therapy excluding anti-viral therapy and observed for efficacy. test group will recruit 548 participants who will be given azvudine + conventional therapy other than antiviral\*5 mg/day, oral, up to 7 days (1 mg/tablet). control group will recruit 548 who will be given placebo + conventional therapy other than antiviral\* 5 tablets/day, oral, up to 7 days.

Eligibility criteria:
inclusion criteria: * (1) an age of 18 years or over (inclusive); (2) not more than five days since the development of covid-19 symptoms, and positive for nucleic acid or antigen test for covid-19 within five days before enrollment; (3) presence of at least one symptom related to covid-19 infection at the time of enrollment; (4) agreement to practice effective birth control (for females of child-bearing potential); (5) presence of at least one high risk factor for severe covid-19 infection: * age ≥ 60 years; * bmi\>25； * fever (body temperature ≥ 38℃) for ≥ 3 days; * current smokers (still being smoking within 30 days before enrollment and have used at least 100 cigarettes up to date); * immunosuppressive diseases, including but not limited to: myelosuppression or organ transplantation or primary immunodeficiency disease; prolonged use of immunosuppressive agents (≥ 20 mg/d for at least 14 days in the case of prednisone within the last 30 days); biologic therapy (such as infliximab, etc.); use of immunomodulators (including but not limited to methotrexate, azathioprine, etc.); radiotherapy and/or chemotherapy for any malignancies within 90 days (for chest radiotherapy, this time interval should be more than 6 months); * chronic lung disease (such as asthma requiring intervention daily, bronchiectasis, copd, pulmonary hypertension, osas, interstitial lung disease, etc.); * hypertension; ⑧ cardiovascular diseases (previously diagnosed as myocardial infarction or stroke, tia (transient ischemic attack), cardiac insufficiency, angina pectoris requiring nitrate therapy, cabg, post-pci, post-carotid endarterectomy and aortic bypass surgery, etc.); ⑨ type 1 or type 2 diabetes; ⑩ neurodevelopmental abnormalities (such as cerebral palsy, down's syndrome) or other genetic or metabolic syndromes and severe congenital malformations; ⑪ active tumors (excluding localized skin cancer); ⑫ no vaccination against covid-19 exclusion criteria: * (1) known or suspected allergy to the components of azvudine tablets; (2) patients diagnosed as severe or critical covid-19 infection (severe: 1. shortness of breath with rr ≥ 30 breaths/min; 2. oxygen saturation ≤ 93% when inhaling air at rest; 3. partial pressure of arterial oxygen (pao2) / fraction of inspired oxygen (fio2) ≤ 300 mmhg; 4. progressive worsening of clinical symptoms, and obvious lesion progression \> 50% on lung images within 24 to 48 hours. critical: 1. respiratory failure, requiring mechanical ventilation; 2. shock; 3. concomitant organ failure, requiring care in icu); (3) patients with severe liver disease (total bilirubin \[tbil\] ≥ 2 × upper limit of normal (uln), alanine aminotransferase (alt) and aspartate aminotransferase (ast) ≥ 3 × uln; (4) patients with severe renal insufficiency (glomerular filtration rate ≤ 60 ml/min/1.73 m2) or currently on continuous renal replacement therapy, hemodialysis, and/or peritoneal dialysis; (5) patients with malabsorption syndrome or any other condition compromising gastrointestinal absorption, or patients requiring parenteral nutrition or with difficulty in taking the investigational product orally; (6) known hiv infection; (7) presence of diabetic ketosis or hyperosmolar hyperglycemic state (hhs); (8) total neutrophil count \< 750 cells/l; (9) pregnant or lactating women or those who plan to have a child during participation in this study and within six months after the end of this study; (10) currently participating in another clinical trial or currently using another investigational product; (11) presence of other active infections (must be etiologically confirmed) in addition to covid-19 infection; (12) presence of any comorbidities requiring hospitalization and/or a surgical procedure within 7 days prior to the start of this study or a comorbidity considered life-threatening within 30 days prior to the start of this study; (13) patients who have received or are expected to receive convalescent plasma for covid-19; (14) previous treatment with anti-viral agents that have been proved to be effective against covid-19, including but not limited to nirmatrelvir/ritonavir or molnupiravir (this criterion does not apply to use of glucocorticoids for reasons other than covid-19); (15) other conditions that make it inappropriate for the participant to take part in this trial at the investigator's discretion.